I have a system that has worked perfectly. I wear a tube style thing I can pull and down easily. I walk with it up and the minute no one is close to me I pull it down. If I encounter someone I pull it up until they pass unless they are doing the same thing in which case we smile at each other and keep going.
But then, I’m not sick so I can’t spread, even if I’m asymptomatic.
My wife just bought a couple of those things. 92% polyester and 8% spandex.
I emailed them and asked if any protection from COVID.
Response: Our Cooling masks have no medical value...
My wife doesn’t care (Finally !) It’s about how it looks...she’s way Irish.